Locals are postage stamps with limited validity. They can often be restricted to a city, town, district or particular mail route. Sometimes the issuing authority may be a government, national or local, or even a private individual or organisation. Some local postage stamps fulfilled genuine needs but many are produced to exploit collectors. Their value is often directly related to legitimacy; for example, many early U.S. local posts served proper purposes and are valuable, but issues for such dubious off-shore British entities such as Staffa do not share their distinction.